How Much Do You Know About Seamless Pipes?

Seamless steel pipe is a kind of round, square and rectangular steel with hollow section and no joints around. Seamless steel pipes are made of steel ingots or solid billets through perforation, and then hot rolled, cold rolled or cold drawn. Seamless steel pipe has a hollow section, which is widely used as a pipeline for conveying fluid. Compared with solid steel such as round steel, the steel pipe has the same bending and torsional strength, and its weight is lighter. It is an economic section steel, which is widely used to manufacture structural parts and mechanical parts

Production process of seamless steel pipe

① Main production process (main inspection process) of hot rolled seamless steel pipe:

Preparation and inspection of pipe blank → heating of pipe blank → piercing → pipe rolling → reheating of raw pipe → sizing (reducing) → heat treatment → straightening of finished pipe → finishing → inspection (nondestructive, physical and chemical, bench test) → warehousing

② Main production process of cold rolled (drawn) seamless steel pipe

Blank preparation → pickling and lubrication → cold rolling (drawing) → heat treatment → straightening → finishing → inspection

Application and classification of seamless steel pipe

Application: seamless steel pipe is a kind of economic section steel, which plays a very important role in the national economy. It is widely used in petroleum, chemical industry, boiler, power station, ship, machinery manufacturing, automobile, aviation, aerospace, energy, geology, construction, military industry and other departments.

Classification:

① Divided by section shape: circular section pipe and special-shaped section pipe

② By material: carbon steel pipe, alloy steel pipe, stainless steel pipe and composite pipe

③ According to the connection mode: threaded connection pipe and welded pipe

④ By production mode: hot rolled (extruded, jacked and expanded) pipe, cold rolled (drawn) pipe

⑤ By use: boiler pipe, oil well pipe, pipeline pipe, structural pipe, fertilizer pipe

Development History of Seamless Steel Pipe

Seamless steel pipe production has a history of nearly 100 years. The German Mannesmann brothers first invented the two roll cross rolling piercer in 1885, and the periodic pipe mill in 1891. In 1903, the Swiss r.c.stiefel invented the automatic pipe mill (also known as the top pipe mill). After that, various extension mills such as the continuous pipe mill and the top pipe mill appeared, which began to form the modern seamless steel pipe industry.

In the 1930s, due to the adoption of three roll pipe rolling mill, extruder and periodic cold rolling mill, the variety and quality of steel pipes were improved. In the 1960s, due to the improvement of continuous pipe mill, the emergence of three roll piercer, especially the successful application of stretch reducing mill and continuous casting billet, improved the production efficiency and enhanced the competitiveness between seamless and welded pipes. In the 1970s, seamless pipe and welded pipe were going hand in hand, and the world steel pipe output was increasing at a rate of more than 5% per year.

Since 1953, China has attached great importance to the development of seamless steel pipe industry, and has initially formed a production system for rolling various large, medium and small pipes.